1. Field of the Invention
The present invention relates to a two-mass vibratory feeder and more particularly, to a mechanism for changing the natural frequency of the feeder.
2. Description of the Prior Art
In a vibratory feeder, a frame, which carries an article or material container, is supported by leaf springs secured to a base. The base, springs and the frame (with container) constitute a spring-coupled two-mass system in which the frame and container (which constitute one mass of the system) is oscillated by a motor with respect to the base (which constitutes the other mass of the system). The motor creates a vibratory driving force of a predetermined frequency, and it is desirable to have the natural frequency of the spring-coupled two-mass system near the frequency of the motor to minimize the power consumed in the feeding operation.
It is therefore desirable to be able to adjust the natural frequency of the system in order to "tune" the two-mass system for most efficient operation. One previously known method of adjusting the frequency of the system is to modify the spring system.
Usually, the spring system by which the frame is mounted to the base consists of sets of leaf springs clamped to both the frame and the base. The removal (or addition) of a leaf from a set is not only difficult and awkward, but it frequently results in too great a change in the frequency of the system.
Accordingly, it is one object of the present invention to provide an improvement in a spring system for a feeder so that the spring system can be easily modified to change the natural frequency of the feeder.
It is another object of the present invention to provide an improvement in a spring system for a feeder so that adjustment of the frequency of the feeder in small increments can easily be made.
It is yet another object of the present invention to provide an improved spring system for a spring-coupled two-mass vibratory feeder in which fine adjustment of the torsional natural frequency of the system can be easily effected.